Core for hollow bodies of concrete and the like



April 2, 1935. LEGGAT r AL 1,996,678

CORE FOR HOLLOW BODIES OF CONCRETE AND THE LIKE Filed July 13, 1935Patented Apr. 2, 1935 5 g 1,996,'6'7& l

- 1 I 396,678 Scone. FOR 11, woweomes F vouchers i Rohertfllzeggat. and..Johannes comelis Pieter heemhuis li ie ifltiai .Zlhfansvaal, SouthAfrica H Application my 13, leesgjserialno. 680.308. I IrrUnion of SouthAfrica July 28,1932 I, 1 i ftfoaims. (CL-25412.8) The presentinvention.was tea ing 1101:; 1 sniall'relatively to J breadth and he giitgand lowbodies" made. of hardened plasticfmaterialt it has 'a vertieal'cavity orpreferably two vet'- such. as hollow, concrete jbuildi'ng bl'ocksendtical cavities 3 which are.correspondinglypi con i panels. "siderable.breadtlfand;heightbut'narrQw.The

5 An object or the inventions retains col f formation .ofjs ch cavi i bymownam tn q s lapsible core, which whilst being" rigid use, is presentsconsiderabledifliculties; 2 adapted so to collapse'asslibstantially todi-f "The mouici nowa .compris sthe base minish both its dimensionstransverse to the; the/four walls'fij, 5Z5, Whiohfare s'eparably helddirection in which it isfto be Withdrawmso that; oeether byimeanscitric-bol s. Thewallsafig 10 it can. be, withdrawn without drag on the.lsurjmould.thelhorizontal'edges of the panelandtllelo faces of thecavity. it forms. walls'fifiythe'Verticaledges'thereof. The cores Aspecific object of the invention is to provide' indicated generally, byf l,1 Y consequently extend a core of this character, which cambe made.between the Walls 5,5]; and parallel'with'the walls,

of considerable dimensions thedirection 5.6). (They, areconvenientlysuppdrted in pos which it is to be withdrawn and in onedimention'b'y seating at theirend's intlie apertures 8 15 siontransverse thereto, whilst being of small diin the walls 5, whichapertures also determine mensions in the other transverse direction. Athe expanded size of the core; The base 4 core or" this kind permits theproduction of holmoulds one of the fiat faces 9 of the panel. The lowconcrete building panels of considerable concrete is poured into theopen top of the mould height and width and of small thickness. and thesecond flat facet of the panel is formed 20 Another object is to providea core which proby screeding the surface of the concrete level I ducesan untapered cavity and which permits with the tops of the walls. I theuse of a wet concrete mix. Each core 1 comprises the two similar unitsAccording to the invention, a core comprises liLlt. Each unit comprisesthe two similar leaves a unit consisting of apair of hinged leavesadapt- "3, eac having a flat portion and a bent end 25. ed to be spreadapart in one direction transverse portion said end portions are ed by tothe direction of withdrawal of the core and the hinge l2. 7 therebydefine a cavity and to be collapsed about When the core is assembled inits moul the hinge with a movement wholly within the form (Figure III),the two units are arranged opcavity so defined, and comprising also asecposite one 91 and p d Ou SO t at the 30 0nd unit which completes thecore surface beedges l3 of the leaves are in contact with one tween thespread-apart edges of said leaves and another and the flat portions ofthe leaves are which permits the first unit, when collapsed, vto alinedwith one another. The core thus prebe moved in a second directiontransverse to sents a. continuous outer surface which defines thewithdrawing movement. Said second .unit the cavity to be produced withinthe panel.v V v would usually be a hinged pair of leaves like The coreis sustained inits expanded form by the first unit, the units beingarranged oppothe end'covers l4 and the centralbar [5, 15a. site oneanother with the edges of their re- The end covers M carry inwardlyprojecting ribs spective leaves in contact. [6 which hold'the leavesapart and also curved V v 40 In the accompanying drawing the inventionis ribs 11 which fit into the curved ends of the units 40 illustrated ina form suitable for curing the thin and so maintain the core at itsproper breadth. concrete panels above referred to; Said ribs l6 and 11,being short, are easily in- Figure' I shows the panel; serted into andwithdrawn from the leaves; and

Figure II is a perspective view' of the panel they are tapered tofacilitate such movements. 7

mould with some parts removed and other parts 'Ihecentral bar I5, l5a,however, extends the 45 displaced, the scale being larger than that offull length of the core and is therefore made col- Figure I. lapsible tofacilitate its insertion and withdrawal. I Figure III is a horizontalsection on a plane It comprises the two bar members 15 and I501.conindicated by III in Figure I. nected'and maintained parallel with oneanother 5 Figure IV is similar to Figure III, showing the by theparallel links 18, thus permitting the memcore in process of removal.bers I5; l5a to come together to reduce the effec- The panel 2 is of thekind referred to in; the tive height of the'bar, and to be separated toinspecification of our application for Patent No. crease the effectiveheight of the bar. Each bar. 657 298, filed February 17, 1933. It isofconmember has screw-threaded stem l9 which exsiderable breadth andheight; but its width is tends through hole 20 to the adjacent end coverI4 and is there providedWith a nut 2| which bears on the outer face ofthe cover.

The leaves of the core are provided on theirv inner faces with ribs 22for positioning the bar- I5, I So. The leaves having been seated in theapertures 8,, the bar I 5. Main its collapsed condition isslid-between.theribs 22. vThe end covers M are slipped over the stems l9, and thenuts 2| are screwed up onto the covers; Thereby the ribs [6, ll of thecovers are firmly forced be- '1 tween the leaves and also the barmembers l 5, 15a;- are traversed relatively to one another to expand thebar, both operations thus expandingtliecore and holding it rigid againstthepressure of'the concrete. I I v 7 When the concrete has been cast andbecome set, the nuts 2| are removed, the 'en'cl covers l4 withdrawn andthe bar l5, I5a is also withdrawn 7 after being collapsed. Theleaves ofone core unitare then pressed towards one another as indicated in FigureIV was to detach them from the concrete. As the hinge i2 is almost attheclosed end of the unit, the collapsing movement of all points of theleaves is distinctly'inward away fromjthe concrete face and is thereforereadily accomplished without danger of damaging said face. Such movementis least in thearea near to'the drawn from the panel endwise. The secondunit is then similarly manipulated and withdrawn.

We claim: 1. The combination of a mould having opposite f wallsapertured to form seatings for a core and to determine the expanded sizethereof, an open ended core seated in said apertures, end covers for thecore having projecting means on their inner faces adapted to enter thecore ends and expand them, a bar comprising connected units adapted. tobe longitudinally moved relatively to one another and thereby vary theeffective width of the' bar, said units having ends projecting throughthe covers, means on said unit ends for pressing on the outside of thecovers to force their projections into the core ends and simultaneouslyto exert tension on the bar unit ends and thereby expand the bar withinthe core.

a 2. The combination of a mould having opposite walls apertured to formseatings for a core and to determine the expanded size. thereof, a coreseated in'said apertures and comprising two similar units; each unitconsisting of a pairof hinged leaves adapted to be spread apart aboutthe hingesin a direction transverse to the mould walls, saidunits beingarranged opposite to one v another with the edges of theirleavestogether; means adapted to enter the ends of the core and expandthe same. and an expansible bar extending between the edges of theleaves to support the latter in their expanded position.

ROBERT LEGGAT. JOHANNES CORNELIS PIETER LEEMHUIS.

